Improvement in operating slide-valves



l P. PEABTREE. Operating Slide-Valves.

Patented Dec.24, 1872.

@ummm UNITED STATES vRAJrEiv'r FFICE.

.IMPROVEMENT IN OPERATING SLIDE-VALVES.

Specification forming part of Letters Patent No; 134,218, dated December 24, 1872.

To all whom 'it may concern:

Be it known that I, PETER PEARTREE, of Lansingburg, in the county of Rensselaer and State of New York, have invented a new and useful Improvement in Device for Operating Slide Va1ves, of which the following is a specification:

Figure 1 is a top view of a steam-engine to which my improvement has been applied. Fig. 2 is aA side view of the same, partly in section, through the line w Fig. l. Fig. 3 is a detail cross-section taken through the line y y, Fig. 1.

Similar letters of reference indicate corresponding parts.

My invention has for its object to furnish an improved device for operating the valve of a steam-engine, which shall be so constructed as to enable the steam to be cut off at any desired part of the stroke, and which will operatethe valve so as to give a lead, which may also be regulated at will; and it consists in the construction and combination of the various parts of the device, as hereinafter der; C, the piston-rod; D, the cross-head; E, the ways upon which the cross-head works;

F the connecting-rod, one end of which is pivoted to the cross-head D, and the other end to the`crank G. H is the valve-seat, in which the ports are formed. The valve-chest is removed to expose the valve I, which moves back and forth upon the seat H, opening and closing the ports alternately. J is the va-lvestem, the outer end of which is pivoted to the arm K, the other -end of which is pivoted to the stud L, to the upper end of which is attached a block, M, upon the inner upper part of which, near its ends, are formed projections m'. '.lhe inner upper part of the block M, between the projections m', is recessed, as shown in Figs. 1 and 2. N is a block, placed in a trough or guide, O, attached to the cross-head D, the sides of which are designed to prevent any lateral movement of the block N. The inner end ofthelblock N is pivoted to the vsides of the guide O, near their inner ends,

as shown in Figs. 1 and 3. The outer end of the block N rests upon the upper side of the block M.

By this construction, as the cross-head D moves in either direction from the central part of its stroke, the outer end of the block N slides along the upper surface of the block M, over the top` of the projection m', and drops down upon the outer side of said projection. As the cross-head begins its return stroke the end of the block N strikes against the inclined side of the projection m', which operates the block M and opens the valve to admit the steam. lThe forward end n of the block N and the projections m of the block M are detachable, so that when worn they may be easily detached and replaced with new ones.

The lower end of the stud L is attached to the outer end of the bar P, which is pivoted near its center to a cross-bar of the bed A. To the other or inner end of the bar P is attached a cross-head, Q, the upper part of the outer side of which is rabbeted, as shown in Figs. 1, 2, and 3. To the vertical shoulder formed by the rabbet at its ends are adjustably secured wedge-shaped blocks It. In the rabbet of the cross-head Q slides a block, S, adjustably attached tothe under side of the end of the cross-head I).

By this construction, after the valve has been opened bythe action of the blocks NM, as the cross-head B advances the block S strikes against the shoulder of the cross-head Q, Whichoperates the pivoted bar P and closes the valve or cuts off the steam. As the crosshead D continues to advance the block S strikes against the inclined or wedge shaped blocks R, which moves the bar l? a little'further, and slightly opens the valve in front of the piston just before it completes its stroke. The lead thus (btained may be regulated as desired by adjusting the wedge-shaped blocks It nearer to or further from I the center of theI cross-head Q.

,The point at which the steam is cut olf may be regulated by adjusting the block S upon the cross -head D, so that the cross -head D may move a greater or less distance before the block S comes in contact with the crosshead Q.

shaped adjustable blocks R with the erosshead Q, pivoted bar P connected with the stem J of the valve I, and with the block S attached to the cross-head D of the piston-rod C, for giving a lead, substantially as herein shown and described.

PETER PEARTREE.

Witnesses:

EUGENE HYATT, Gno. H. HEARMON. 

